Many mobile computing devices, such as mobile phones, are configured to utilize a variety of context-aware applications in order to provide dynamic feedback to users. As used herein, the term “context-aware” refers to a capability of certain applications or programs implemented on mobile computing devices to detect, or sense, the changing environment and react appropriately. Such context-aware applications often rely on continuous or frequent sensing of users' context. A user's context may include, for example, information such as a location, a transportation mode, a group state of the user, or a work state of the user, among others. However, acquiring contextual information can be expensive on battery-operated mobile devices, since the sensing of the user's context may consume a large amount of battery power.